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Publication numberUS4864015 A
Publication typeGrant
Application numberUS 07/274,085
Publication dateSep 5, 1989
Filing dateNov 21, 1988
Priority dateApr 8, 1988
Fee statusPaid
Publication number07274085, 274085, US 4864015 A, US 4864015A, US-A-4864015, US4864015 A, US4864015A
InventorsJames A. Cella, Deborah A. Haitko
Original AssigneeGeneral Electric Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method for making thianthrene dianhydride and polyimides obtained therefrom
US 4864015 A
Abstract
A method is provided for making 9,10-dithiaanthracene-2,3,6,7-tetracarboxylic acid dianhydride. Polyimides having improved oxidative stability also are provided which can be made intercondensing organic diamine and the aforementioned dianhydride or a dianhydride mixture.
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Claims(14)
What is claimed and sought to be protected by letters patent of United States is as follows:
1. Polyimides comprising chemically combined units of the formula, ##STR8## where R and R1 are selected from C.sub.(1-8) alkyl radicals, C.sub.(1-8) alkoxy radicals and C.sub.(6-14) aryl radicals, R2 is a C.sub.(6-30) divalent, aromatic organic radical, and a and b are whole numbers equal to 0 or 1.
2. A polyimide in accordance with claim 1, where R2 is ##STR9##
3. A polyimide in accordance with claim 1, where R2 is ##STR10##
4. Polyimides resulting from the intercondensation of substantially equal molar amounts of aryldiamine and a mixture of thianthrene dianhydride and another dianhydride.
5. A polyimide in accordance with claim 4, where the other dianhydride is phthalic anhydride.
6. A polyimide in accordance with claim 4, where the other dianhydride is pyromellitic dianhydride.
7. A polyimide in accordance with claim 4, where the other dianhydride is benzophenone dianhydride.
8. A polyimide in accordance with claim 4, where the other dianhydride is oxydiphthalic acid anhydride.
9. A polyimide in accordance with claim 4, where the other dianhydride is sulfur diphthalic acid anhydride.
10. A polyimide in accordance with claim 4, where the other dianhydride is hydroquinone dianhydride.
11. A polyimide in accordance with claim 4, where the other dianhydride is bisphenol-A dianhydride.
12. A polyimide in accordance with claim 4, where the other dianhydride is biphenol dianhydride.
13. A composite comprising carbon fiber and polyimide consisting essentially of chemically combined units of the formula, ##STR11## where R and R1 are selected form C.sub.(1-8) alkyl radicals, C.sub.(1-8) alkoxy radicals and C.sub.(6-14) aryl radicals, R2 is a C.sub.(6-30) divalent, aromatic organic radical, and a and b are whole n umbers equal to 0 or 1.
14. The polyamic acid intercondensation reaction product of substantially equal molar amounts of organic diamine of the formula,
NH2 R2 NH2,
and a dianhydride selected from the class consisting of thianthrene dianhydride of the formula, ##STR12## and a mixture of thianthrene dianhydride and another dianhydride, where R and R1 are selected from C.sub.(1-8) alkyl radicals, C.sub.(1-8) alkoxy radicals and C.sub.(6-14) aryl radicals, R2 is a C.sub.(6-30) divalent, aromatic organic radical, and a and b are whole numbers equal to 0 or 1.
Description

This is a division of application Ser No. 179,370 filed Apr. 8, 1988, now U.S. Pat. No. 4,814,466.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of copending application Ser. No. 045,118, now abandoned filed May 4, 1987, assigned to the same assignee as the present invention and incorporated herein by reference.

The present invention relates to a method for making 9,10-dithiaanthracene-2,3,6,7-tetracarboxylic acid dianhydride, or derivatives, referred to hereinafter as "thianthrene dianhydride" and to polyimides having glass transition temperatures in excess of 400° C.

Prior to the present invention, aromatic polyimides were generally recognized as organic materials having superior solvent resistance and temperature resistance. Aromatic polyimides can generally be made by intercondensing aromatic dianhydrides with aliphatic or aromatic diamines. One technique for improving the glass transition temperature (Tg) of aromatic polyimides is by intercondensing aromatic dianhydrides with aromatic diamines. Further improvements can be achieved in aromatic polyimide properties by utilizing a particular aromatic dianhydride to provide a polyamic acid which is convertible to a polyimide having higher temperature resistance and solvent resistance upon heating.

The present invention is based on the discovery that aromatic polyimides having glass transition temperatures in excess of 400° C. can be made by intercondensing one or more aromatic diamines, such as methylene dianiline or metaphenylene diamine with thianthrene dianhydride having the formula, ##STR1## where R, and R1 are selected from the same or different C.sub.(1-8) alkyl radicals, C.sub.(1-8) alkoxy radicals, and C.sub.(6-14) aryl radicals, and a a and b are whoel numbers equal to 0 or 1.

STATEMENT OF THE INVENTION

There is provided by the present invention, polyimides comprising chemically combined units of the formula, ##STR2## where R and R1 are as previously defined and R2 is a C.sub.(6-30) divalent aromatic organic radical.

There is also included by the present invention, a method for making thianthrene dianhydride of formula (1), comprising effecting reaction between an alkali metal sulfide and an N organo-4,5-dihalophthalimide of the formula, ##STR3## where R and a are as previously defined, R3 is selected from monovalent C.sub.(1-14) hydrocarbon radical, or C.sub.(1-14) monovalent hydrocarbon radical substituted with radicals inert during halogen displacement, or substitution reactions, to produce the corresponding bisimide of the formula, ##STR4## where R, R1, R3, a and b are as previously defined.

Hydrolysis of the thianthrene bisimide of formula (4) in the presence of an aqueous base followed by acidification and ring closure provides the thianthrene dianhydride of formula (1).

Polyimides consisting essentially of chemically combined units of formula (2) can be made by the intercondensing substantially equal molar amounts of thianthrene dianhydride of formula (1) with organic diamine of the formula,

NH2 R2 NH2,                                 (5)

where R2 is as previously defined in the presence of an inert organic solvent to produce the corresponding polyamic acid. Polyamic acid solutions having from 5% to 50% by weight of solids, based on the total weight of solution, can be used in combination with filters, such as carbon fibers, or glass fibers, to produce high temperature composites.

Radicals which are included within R and R1 of formula (1) are for example C.sub.(1-8) alkyl radicals, such as methyl, ethyl, propyl, butyl, pentyl; aryl radicals, such as phenyl, xylyl, tolyl, naphthyl and halogenated derivatives thereof, for example of chlorophenyl, bromonaphthyl, etc. Radicals which are included within R2 of formulas (2) and (5) are for example phenylene, phenyleneoxyphenylene and divalent radicals of the formula, ##STR5##

Radicals which are included within R3 of formula (3) are for example C.sub.(1-8) alkyl radicals such as methyl, ethyl, propyl and C.sub.(6-14) aryl radicals such as phenyl, naphtyl, anthryl and such aryl radicals substituted with radicals neutral during intercondensation, displacement or substitution reactions.

Some of the aryl diamines which are included within formula (5) are, for example, ##STR6##

In the practice of one form of the invention substantially equal molar amounts of the dihaloimide of formula (3), and an alkali metal sulfide, such as sodium sulfide or potassium sulfide is contacted in the presence of an inert organic solvent under substantially anhydrous conditions at a temperature in a range of from 50° C. to 200° C. Recovery of the bisimide can be readily achieved by standard procedure such as filtration, washing with organic solvent and drying.

Hydrolysis of the bisimide can be achieved by agitating the bisimide in the presence of an aqueous base such as an aqueous solution of an alkali metal hydroxide, for example potassium hydroxide along with heating the mixture to reflux. Separation of water and organic amine can be readily effected and the process continued, with the addition of water until the distillate is substantially neutral. The resulting tetraacid can be separated by standard means followed by dehydration and recrystallization.

The intercondensation of thianthrene dianhydride and organic diamine to a polyamic acid can be achieved by employing substantially equal molar amounts of the reactants in the presence of a suitable inert organic solvent preferably, an aprotic dipolar organic solvent can be used under substantially anhydrous conditions at ambient temperatures. Suitable organic solvents are, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

If desired, thianthrene dianhydride of formula (1) can be blended with up to about 2 to 75 mole percent of other dianhydrides, such as phthalic anhydride, pyromellitic dianhydride, benzophenone dianhydride, oxydiphthalic acid anhydride, sulfur diphthalic acid anhydride, hydroquinone dianhydride and bisphenol A dianhydride.

The resulting polyamic acid can be applied onto a substrate, or mixed with an appropriate reinforcing filler, such as a carbon fiber, or glass fiber. There can be utilized from about 50 to 500 parts of fiber, per 100 parts of polyamic acid. The polyamic acid can be heated under a slight vacuum under nitrogen at a temperature in the range of from 30° to 100° C. and thereafter imidized by programmed heating at temperatures in the range of between 100° C. to 400° C.

In order that those skilled in the art will be better able to practice the present invention, the following examples are given by way of illustration and not by way of limitation. All parts are by weight.

EXAMPLE 1

A mixture of 6.006 g (77 mmol) of anhydrous sodium sulfide, 17.57 g (76.39 mmol) of N-methyl-4,5-dichlorophthalimide and 300 ml of dry N,N-dimethylacetamide was heated to 160° C. for a two hour period with stirring. A bright yellow solid separated from the reaction mixture. After the mixture had cooled to room temperature, it was filtered and a crude solid was recovered. The solid was washed with ether and dried overnight in a vacuum oven. The light yellow solid weighed 12 g or a yield of 82.2%. It had a melting point of 392.7° C. Based on method of preparation, the solid was N,N'-dimethylthianthrene-2,3,6,7-tetracarboxylic acid bisimide. The identity of the compound was further confirmed by field desorption mass spectrometry which exhibited one signal at m/c 382 corresponding to the molecular ion of the substance.

A mixture of 31 g (81 mmol) of the above thianthrene bisimide, 32.3 g (486 mmol) of KOH pellets (85%) and 200 ml of water was heated to reflux while stirring. Water and methylamine were continuously distilled from the mixture and replaced with fresh water. There was obtained 14.42 g or a 50% yield of thianthrene dianhydride after the corresponding tetraacid was vacuum oven dried for a period of 16 hours. The dianhydride was obtained by recrystallization of the resulting solid from orthodichlorobenzene containing a trace of acetic anhydride. The resulting dianhydride had a melting point (DSC) of 349° C., mass spectrum (high reoslution EI) calcd for C16 H4 O6 S2 to 355.9449; Found 355.9441.

Example 2

A mixture of 400 mg (2.0 mmol) of 4,4,-diaminodiphenylether, 712 mg (2.0 mmol) of thianthrenee dianhydride and 6.0 ml of dry DMAC was stirred at ambient temperature for one hour. It was then spread on a dry glass plate. The sample was heated overnight under a slight vacuum with an nitrogen bleed at 70°-75° C. The resulting amic acid film was then imidized by a programmed heating as follows: 100° C., 1 hour; 200° C., 1 hour, 300° C., 30 minutes; 400° C., 15 minutes; 450° C., 15 minutes. The resulting film was dark amber and somewhat brittle. Yield 815 mg (78.4%); Tg (TMA)=412° C. Based on method of preparation the product was a polyimide consisting essentially of chemically combined units of the formula, ##STR7##

The above procedure was repeated except in place of the 4,4,-diaminodiphenylether there was utilized methylenedianiline (MDA), m-phenylenediamine (MPD), p-phenylenediamine (PPD), oxydianiline (ODA) and a mixture of equal molar amounts of MPD and PPD. The Tg of the polyimides which were obtained from the respective aryldiamines are shown as follows,

______________________________________  Diamine    Tg______________________________________  MDA        395  MPD        405  PPD        400  ODA        412  MPD/PPD(1/1)             399______________________________________
EXAMPLE 3

A polyimide was prepared in accordance with the method of Example 2, utilizing substantially equal molar amounts of p-phenylenediamine and thianthrene dianhydride. A film of the polyimide was cut into strips and weighed in glass vials. The weights of the polyimide strip ranged from 0.3-0.5 gms.

Several commercially available polyimides, such as Kapton® polyimide, and Upilex® a polyimide also were evaluated following the same procedure. The vials were placed in a hot block maintained at 371±5° C. Sample weights were taken at regular intervals over a 150 hr period. The isothermal weight loss of the samples over a 100 hr and 150 hr period of 371° C., indicating "thermal oxidative stability" is shown as follows:

______________________________________Polyimide   Tg    100 hrs 150 hrs______________________________________Kapton ®       399        15.3    23Upilex ®       283        5       16NR-150      367        3.9     6.1Ultem ® 215        3.8     4.9Thianthrene 400        2.2     2.6______________________________________

The above results show that thianthrene polyimide is more oxidatively stable than Kapton® polyimide made from pyromellitic acid dianhydride, Upilex®, made from biphenylene dianhydride, NR-150, and Ultem® polyetherimide made from bisphenol-A dianhydride.

EXAMPLE 4

A solution was stirred for 1 hour at 50° C. under nitrogen consisting of 1 gram of thianthrene dianhydride, 1 gram of 4,4'-bis(phthalic anhydride)oxide, 0.6526 grams of paraphenylenediamine and 16 ml. of N,N-dimethylacetamide. A film from this solution was cast upon a dry Pyrex plate. The plate and the film were heated in a vacuum oven for about 12 hours using a slow nitrogen bleed at a temperature of up to about 70° C. The film was then gradually heated at 100° C. for 1 hour, 180° C. for 1 hour, 250° C. for 20 minutes, 300° C. for 20 minutes, 350° C. for 20 minutes and 400° C. for 20 minutes. The resulting film was amber in color and it had a Tg as determined by TMA of 396° C.

EXAMPLE 5

A solution of 1.000 grams of thianthrene dianhydride, 1.000 grams of bisphenol dianhydride, 0.5298 gram of phenylenediamine and 12 ml. N,N-dimethylacetamide was stirred for 2 hours while it was slightly warmed. The thickened mixture was then poured onto a Pyrex plate and heated in accordance with the procedure of Example 4. The Tg of the resulting film was found to be 379° C. as determined by TMA.

EXAMPLE 6

There was added with stirring 13 ml of dry N,N-dimethylacetamide to a mixture under a nitrogen atmosphere consisting of 1.000 gm of thianthrene dianhydride, 1.000 gm of 4,4'-bis(phthalic anhydride) oxide, and 0.6526 gm of p-phenylenediamine. An additional 3 ml of N,N-dimethylacetamide was then added. The pale yellow solution thickened after stirring for one hour at 50° C. A film from this solution was cast upon a dry Pyrex plate. The plate and film were heated in a vacuum oven overnight using a slight vacuum, slow nitrogen bleed, and a temperature no greater than 70° C. After about 12 hours, imidization was completed by gradual heating as follows: 100° C. for one hour, 180° C. for one hour, 250° C. for 20 minutes, 300° C. for 20 minutes, 350° C. for 20 minutes, and, finally, 400° C. for 20 minutes. The film was amber in color. Tg, as determined by TMA, was 396° C. Based on method of preparation, there was obtained a polyimide copolymer having chemically comined thianthrene bismide units and bisphthalicimide units.

EXAMPLE 7

In accordance with the procedure of Example 6, additional polyimide copolymers were made by effecting intercondensation of a mixture of thianthrene dianhydride with other aromatic dianhydrides with an appropriate diamine utilizing dipolar aprotic solvents. The following table shows the Tg s obtained from several copolymers resulting from the intercondensation of paraphenylenediamine with mixtures of thianthrene dianhydride and other aromatic dianhydrides, where PA is phthalic anhydride, ODAN is 4,4'-oxyphthalic anhydride, SDA is 4,4'-sulfur bisphthalic anhydride, and HQDA is hydroquinone dianhydride.

______________________________________Anhydride       Tg (°C.)______________________________________1               3921 + 2% PA       3991/ODANa (3/1)           3861/ODAN (1/3)    3071/SDA (1/1)     3961/HQDA (1/1)    355______________________________________
EXAMPLE 8

In accordance with the procedure of Example 6, there was added 12 ml of dry N,N-dimethylacetamide to 1.000 gm of thianthrene dianhydride, 1.000 gm of biphenol dianhydride, and 0.5298 gm of p-phenylendiamine. The mixture washed warm to form a solution. After two hours, the solution thickened. A film was poured onto a Pyrex plate and the imidization was performed, as above, using a temperature gradient. The Tg, as determined by TMA, was 379° C.

Although the above results are directed to only a few of the very many variables which can be used in the practice of the present invention, it should be understood that the present invention is directed to a much broad variety of polyimides and methods for making them as shown in the description preceding these examples.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4716216 *Nov 19, 1986Dec 29, 1987General Electric CompanyHigh solvent resistance
US4724257 *Jul 14, 1986Feb 9, 1988Mitsubishi Petrochemical Co., Ltd.Aromatic polythioetheramide-imide
US4783522 *Jul 11, 1986Nov 8, 1988Mitsubishi Petrochemical Co., Ltd.Heat resistant molding materials; automobiles, aircraft, electronics
US4808696 *Jun 1, 1987Feb 28, 1989General Electric CompanyFrom dianhydride and/or diimides and alkali metal sulfide
CA879163A *Aug 24, 1971Gen ElectricPolyamide imides
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5177180 *Aug 7, 1990Jan 5, 1993General Electric CompanyHigh temperature mixed polyimides and composites formed therefrom
US5338773 *Apr 19, 1993Aug 16, 1994Dentsply Research & Development Corp.Dental composition and method
US5514444 *Jun 17, 1994May 7, 1996Hexcel CorporationFiber reinforced polyimide honeycomb for high temperature applications
US5688848 *Oct 25, 1996Nov 18, 1997General Electric CompanyPolyimide composition and polyimide composite
US5716677 *Mar 21, 1996Feb 10, 1998Ohio Aerospace InstituteOxidation resistance
US5955514 *Dec 22, 1997Sep 21, 1999Dentsply Research & Development Corp.Polymerizable phosphorus and unsaturated aromatic compounds; storage stability, bonding strength; complexing
US5981620 *Oct 17, 1997Nov 9, 1999Dentsply Research & Development Corp.Polymerizable aryl acid compound, an effective amount of a polymerization initiator, and at least 10 percent by weight of ceramic, metal and/or metal oxide filler particles having a particle size less than 500 microns
US6025460 *Nov 4, 1997Feb 15, 2000Ohio Aerospace InstituteBiphenyltetracarboxylic dianhydride and aromatic diamine are heated until viscosity drops; polyimides from polyamic acids; durable and heat resistant protective coatings
US6500879Jun 15, 1994Dec 31, 2002Dentsply Research & Development Corp.Cement has superior adhesion to tooth without separate acid etching of dentin or enamel; shelf stable glass or ionomer paticles coated with ethylenically unsaturated ester monomers complexed with metal cations of the particle
Classifications
U.S. Classification528/352, 428/473.5, 528/171, 528/125, 528/226, 528/128, 528/229, 528/189, 528/172, 528/185, 528/188, 528/208
International ClassificationC07D495/14, C08G73/10
Cooperative ClassificationC08G73/1064, C07D495/14, C08G73/1085
European ClassificationC08G73/10Q, C08G73/10M2, C07D495/14
Legal Events
DateCodeEventDescription
Aug 18, 2008ASAssignment
Owner name: CITIBANK, N.A., AS COLLATERAL AGENT, NEW YORK
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Owner name: CITIBANK, N.A., AS COLLATERAL AGENT,NEW YORK
Apr 14, 2008ASAssignment
Owner name: SABIC INNOVATIVE PLASTICS IP B.V., NETHERLANDS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GENERAL ELECTRIC COMPANY;REEL/FRAME:020820/0578
Effective date: 20070831
Jan 2, 2001FPAYFee payment
Year of fee payment: 12
Jan 2, 1997FPAYFee payment
Year of fee payment: 8
Nov 23, 1993FPExpired due to failure to pay maintenance fee
Effective date: 19930905
Dec 29, 1992FPAYFee payment
Year of fee payment: 4